Held for Sale and Discontinued Operations (Details Textual) $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($) property	Dec. 31, 2015 USD ($) property	Dec. 31, 2014 USD ($) property
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of properties held for sale	2	1
Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of properties held for sale	1
Revenue related to properties sold | $		$ 0.8	$ 5.7
Expenses related to sale of real estate | $	$ 0.1	0.1	4.7
Impairments related to property held for sale | $	$ 0.1	$ 0.7	8.3
Impairments related to sold property | $			$ 3.7
Number of impaired properties sold			3
Number of impaired properties held for sale	1		4
Number of properties related to gain on sales	1	3